My order recently came in for a bunch of markers from Mechanical Warhorse. These markers are an acrylic and multipart. Two friends and I purchased something like twenty five bases of various sizes. The 100P3 size is pretty bang on for a leman russ or rhino chassis and the 100P4 is pretty good for a land raider. The 100P2 is a little smaller than a dreadnought base but they worked for that and for marking Dark Eldar venoms. In the first game we used them (2v2, 1750/player) we went through I think 20. Of course only you know how many you need and how many vehicles you own. Every time a vehicle exploded it was a bit of a chore to assemble a marker (there are 2 orange/red flames, 1 smoke, the base and the orange flame). After the game I took rough sandpaper to the bottom 1/2 cm of the red/orange and smoke pieces and then super glued them. Now each marker is just 3 pieces and they're much sturdier, easier to store and assemble. If you had a lot of room you could glue the whole marker but I want them to store flat. Your mileage may vary.
As for in game, they're perfect to mark craters from exploded vehicles. Models easily sit on the flat base. My favourite part is the cinematic effect they add to the game. Just look at this cross table image of turn 4 once the dark eldar menace was stopped (he was 10 or 12 of the vehicles). You're not getting this sort of view from old CDs. Also they're precoloured which is a huge plus for people. Depending on your army, you can get enough bases to mark worst case scenario. If the big bases are a bit much for anyone, the small 5 pack of wreckage markers are also really nice (and preglued). The plastic itself (styrene glue doesn't work) is thick and rugged. The edges were also smooth with no need to remove sharp edges. They do balance without being glued but some of the taller smoke ones just seem to work better now that I've glued the flames to the smoke in the centre (not to the base or the cross flames).
I've been looking for years for something that looked good, was not army specific, was durable and easy to use (I'm not painting 20+ markers). I found them here.
The owner of Mechanical Warhorse also provided me with great customer service and despite his ebay store not having what I wanted posted for sale at the time, easily remedied it through an email. My only upset was that customs dinged me 10%. Once these hit the table I was back to being super happy about the purchase as these will definitely become a prominent feature on our group's tables.